Thousands of racegoers cheered and applauded from the stands as the Queen's carriage led the procession down the course. She slipped into a pair of white heels to complete her look.
Prince Charles travelled behind her with Camilla Duchess of Cornwall and Princesses Beatrice and Eugenie.
Men must wear "black or grey morning dress which must include: A waistcoat and tie (no cravats); A black or grey top hat; Black shoes worn with socks".
Prince Edward, Earl of Wessex, Prince Harry, Duke of Sussex, Sophie, Countess of Wessex and Meghan, Duchess of Sussex arrive by carriage to Royal Ascot Day 1 at Ascot Racecourse on June 19, 2018 in Ascot, United Kingdom. During his interview, he revealed that his daughter and Prince Harry could be trying for a baby because Markle wants to be a mom.
The couple married in May, and have carried out several royal engagements since then.
"I was very upset that it wasn't me [walking with her], but the whole world was watching my daughter", Thomas said of the wedding.
The Queen said of the races in the program, according to The Telegraph: "My family and I greatly look forward to Royal Ascot".
At the time she called the situation "deeply personal" and asked for "understanding and respect to be extended" to her dad during the hard time; one would think that after all he put her through, Thomas would've respected her enough to STFU.
Markle's dress for Ascot was more covered-up than we often see her - the Duchess loves an open neckline - but that's due to the conservative dress code of the royal-sponsored event.